The Acoustic Reflex

Contributors

Foreword

Preface


1 Neurophysiological Basis of the Acoustic Middle-Ear Reflex

Anatomy of the Stapedius-Reflex Arc

Basic Characteristics of the Acoustic Middle-Ear Reflex

Effects of Middle-Ear Muscle Contractions

Concluding Remarks

References


2 Impedance Concepts Relating to the Acoustic Reflex

The Impedance at the Probe Tip

The Concept of Impedance

Impedance Changes during the Acoustic Reflex

The Choice of Probe Tone

Concluding Remarks

Appendix: A Mathematical Treatment of the Relationship between Mechanical, Acoustic, and Electrical Impedance

References


3 Theories of Middle-Ear Muscle Functions

Theories of Function: General Historical Background

Review of the Theories of Function

Evolution of a Theory of Choice: Intensity Control-Protection Theory

Comparative Analysis of Middle-Ear Muscle Structure and Function as a Basis for a Revised Theory

Middle-Ear Muscle Function: Prevention of Desensitization, Interference, and Injury

Concluding Remarks

References


4 Evaluation of the Response Time of Acoustic- Immittance Instruments

Definitions

Measurement of the Dynamic Properties of Acoustic- Immittance Instruments

Concluding Remarks

References


5 The Contralateral Acoustic-Reflex Threshold

Measurement Variables

Normal Acoustic-Reflex Thresholds

Low-Level Reflex Thresholds

Temporal Integration of the Acoustic Reflex

Reflex Thresholds for Speech Activators

Infants and Young Children

Effects of Aging

Conductive Hearing Loss

Sensorineural Hearing Loss

Retrocochlear (Eighth-Nerve) Pathology

Central Nervous System Disorders

Concluding Remarks

References


6 Prediction of Hearing Loss from the Acoustic-Reflex Threshold

Methods Predicting the Magnitude of the Hearing Loss

Methods of Identifying the Presence of Hearing Loss

Concluding Remarks

References


7 Magnitude and Growth of the Acoustic Reflex

Intersubject Variability in Immittance Change during Acoustic-Reflex Contraction

The Dynamic Range of the Acoustic-Reflex Growth Function

The Effect of Age on the Acoustic-Reflex Growth Function

The Effect of Activator Frequency on the Acoustic-Reflex Growth Function

The Effect of Probe-Tone Frequency on the Acoustic-Reflex Growth Function

The Acoustic-Reflex Growth Function for Ipsilateral, Contralateral, and Bilateral Stimulation

The Effect of Sensorineural Hearing Loss on the Acoustic-Reflex Growth Function

The Effect of Retrocochlear Pathology on the Acoustic-Reflex Growth Function

The Effect of Conductive Pathology on the Acoustic-Reflex Growth Function

Concluding Remarks

Appendix: Quantification of Acoustic-Reflex Magnitude

References


8 The Ipsilateral Acoustic Reflex

Methods of Acoustic-Reflex Measurement

Ipsilateral Acoustic-Reflex Measurement

Characteristics of the Ipsilateral Acoustic Reflex

Detection of Hearing Loss with Ipsilateral Acoustic-Reflex Thresholds

Commercial Instrumentation

Concluding Remarks

References


9 Acoustic-Reflex Latency: State of the Art

Recording Methods

Stimulus Parameters Affecting Acoustic- Reflex Latency

The Concept of Acoustic- Reflex Latency

The Method of Investigation in Our Laboratory

The Results of Our Investigation

Concluding Remarks

References


10 Acoustic-Reflex Adaptation

Introduction

Measurement Problems Encountered with Acoustic- Reflex Adaptation

Historical Antecedents

Normal Acoustic- Reflex Adaptation Data

Abnormal Acoustic- Reflex Adaptation Data

Recommended Procedures for Obtaining Clinical Measures of Acoustic-Reflex Adaptation

Concluding Remarks

References


11 Acoustic and Nonacoustic Reflex Patterns in Audiologic Diagnosis

Acoustic- Reflex Pathways

Non Acoustic- Reflex Pathways

Diagnostic Applications

Diagnostic Profiles

Concluding Remarks

References


12 Acoustic Reflex in Industrial Noise

General Background

Aims of This Study

General Methods

Results

Discussion

Concluding Remarks

References


13 The Effect of Drugs and Systemic Disease on the Acoustic Reflex

Neuromuscular Junction

Drugs

Systemic Disease

Concluding Remarks

Appendix: Abbreviations and Definitions of Medical Terms

References


14 Acoustic Reflex and Loudness

Introduction

Normal Ears

Conductive Pathology

Cochlear Pathology

Retrocochlear Pathology

Concluding Remarks

References

Index